Olfaction And Taste Flashcards
(96 cards)
1
Q
Sensation of odors that results from the detection of odorous substances aerosolized in the environment
A
Olfaction
2
Q
Sensation evoked by stimulation of taste receptors located in the oropharyngeal cavity
A
Taste
3
Q
Contributes to the experience of flavor by detecting irritating components in smells like ammonia or the “hot” in spicy food like peppers
A
Somatosensory system
4
Q
What is responsible for thermal and textural perceptions in food
A
Somatosensory system
5
Q
Appetite
A
Orexia
6
Q
Lack of appetite
A
Anorexia
7
Q
Lack of smell
A
Anosmia
8
Q
What is smell most important in humans for
A
Learning and smelling poison
9
Q
Plays a role in pleasures associated with eating and with the many scents that make up our world
A
Olfactory system
10
Q
What ar the taste sensations
A
Sweet, salty, sour, bitter, and more recently umami (amino acids)
11
Q
_____ which originates from receptors in the oropharyngeal cavity, is important to determine the acceptance or rejection of foods. This info is relayed by neural pathways that underlie various ingestive and digestive functions
A
Taste
12
Q
What is the sensation of taste though smell
A
Retrosnasal smell, from food
13
Q
What part of the nervous system is the olfactory bulb
A
CNS
14
Q
Where does the olfactory bulb lie
A
Cribiform plate
15
Q
What bone is the cribiform plate on
A
Ethmoid bone
16
Q
Olfactory bulb in relation to the frontal lobe
A
Inferior to the medial aspect of the frontal lobe
17
Q
Where do the olfactory fibers pass through
A
Cribiform plate
18
Q
Receptors responsible for transduction of odor molecules are found in the
A
Olfactory mucosa
19
Q
Where is the olfactory nasal mucosa
A
Roof of the nasal cavity on the inferior surface of the cribiform plate and along the nasal septum and medial wall of the superior turbinate
20
Q
How is the olfactory mucosa different than the respiratory epithelium
A
The olfactory mucosa is yellowish in color and has greater thickness
21
Q
What does the olfactory epithelium contain
A
- olfactory receptor neurons
- supporting cells
- basal cells
- ducts of small glands (Bowmans) that secrete mucous
22
Q
Where are the olfactory receptors found
A
Bodies of bipolar olfactory receptor neurons are found in the basal two thirds of the epithelium
23
Q
Makeup of olfactory receptor
A
-each has a single thin apical dendrite and a nasally located unmyelinated axon
24
Q
The apical dendrite of the olfactory receptor
A
Extends to the surface of epithelium where it terminates in a knob like olfactory vesicles from which 10 to 30 nonmotile cilia arise
25
The unmyelinated axons of an olfactory receptor neuron pass through the lamina proprioceptive and group together into bundles called _______, whihc collectively make up the olfactory nerve (CN1)
Olfactory fila
26
Where do the olfactory film pass through
The cribiform plate and terminate in the olfactory bulb
27
Where is the olfactory bulb
Located on the ventral surface of the frontal lobe in the olfactory sulcus and is attached to the rest of the brain by the olfactory tract
28
Where do the olfactory fila synapse?
Olfactory bulb
29
What type of odorants are more likely to cross the mucus
Hydrophobic such as musk
30
How do hydrophobic molecules cross the mucus in olfactory transduction
By interacting with small proteins called odorant binding proteins
31
After crossing the mucus, what do hydrophobic odorants do
Bind to odorants receptors on the cilia of the olfactory receptor neurons, which causes depolarization of the dendrite of the olfactory receptor neuron
32
What do the axons of the olfactory receptor neuron do
Communicate with the second order neurons in the olfactory tract (in bulb) called mitral cells, which emerge from the caudal portion of he olfactor bulb to form the lateral olfactory tract
33
What is the only system to bypass the thalamus
Olfactory
34
How do the axons of the olfactory tract course
Caudally to terminate in areas on the ventral surface of the frontal lobe, which are broadly defined as the olfactory cortex
35
What are the principal areas making up the olfactory cortex
- anterior olfactory nucleus
- olfactory tubercle
- piriform cortex
- periamygdaloid cortex
- entorhinal cortex
36
What is unique about the olfactory system
The bulb projects directly to the cortex
37
Where does the olfactory cortex send projections
To the orbitofrtonal cortex and insula (also receive taste input)
38
In addition to neocortical projections, the olfactory cortex also sends fibers directly to the
Lateral hypothalamus and hipposcampus
39
Projections from the olfactory cortex to the lateral hypothalamus
Important for feeding behavior and sense of hunger
40
The olfactory cortex projections to the hippocampus
Links olfactory input to centers concerned with learning and behavior (smells bringing back memories)
41
Conductive olfactory deficits
Caused by nasal polyps, septal deviation, and inflammation (blockage)
42
Sensorineural olfactory deficits
Triggered by processes that damage the olfactory receptor neurons or parts of the olfactory CNS (head injuries, neurodegerneative diseases, severe upper respiratory infection)
43
What is considered the primary olfactory cortex in humans
Piriform cortex
44
Affect on smell of seizures originating in the vicinity of the uncut
May begin with an illusion of smell or taste, most often an unpleasant one. May go on to include chewing movements or smacking of lips
45
Seizures that affect the piriform complex that result in illusions of smell and or taste and are accompanied by chewing movements or smacking of the lips
Uncinate seizures
46
The loss of smell (anosmia) or decreased smell can be associated with
Nasal polyps
47
What can nasal polyps result from
Inflamed mucous membranes or allergic reactions and can obstruct the nasal cavities or extend into the nose
48
What are some causes of disrupted sense of smell
```
Nasal polyps
Rhinitis or sinusitis
Head trauma
Features along anterior base of skull
Tumors
Cocaine
Smoking
```
49
What can cause CSF to leak through nose
Fractures along the anteiror base of the skull may cause drainage of CSF into the paranasal sinuses and through the nose (CSF rhinorrhea)
50
What is specific anosmia
Healthy person who is unable to perceive the odor of a particular compound. May be inherited
51
Psychiatric disorders and smell
Patients may experience parosmia, a distortion in a smell or the perception of a smell when no odoer is present
52
Chief complaint of most patients with chemosensory disturbances
Loss or alteration of taste. People confuse taste with flavor
53
Detection of odorous substance
Indicates the integrity of the peripheral nerve and its pathway
54
Identification of the odor
Reveals intact cortical functions
55
If the patient is aware of a smell but cannot recall the name of the scent
The disorder is likely to reside at higher levels of the sensory system (initial symptoms of Alzheimer's)
56
Are olfactory losses unilateral or bilateral?
Either
57
Unilateral olfactory losses
Typically observed subsequent to nasal cavity disease or after tumor associated compression of one olfactory bulb or tract
58
Bilateral olfactory losses (ansomia)
Sustained in response to head trauma or the common cold
59
Olfactory and age
Decline in olfactory function are common
| -the loss occurs gradually and pt often fails to notice. Can affect the palatability of foods
60
What does the dense of taste result from
An interaction between gustatory stimuli and receptor cells located in sensory organs called taste buds
61
Where are taste buds
Tongue and oropharyngeal cavity
62
What are hte lingual tastebuds
- fungiform papillae
- foliate papillae
- circumvallate papillae
63
What are the extralingual taste buds
May not be for taste, but for detection of food and suppression of aspiration into trachea (protect from inhaling food)
64
Fungiform papillae
2-4 taste buds dorsally, anterior 2/3 tongue
65
Foliage papillae
2-9 clefts, taste buds in clefts, posterior margin of tongue
66
Circumvallate papillae
8-12 taste buds in cleft
67
What taste buds are on the anterior 2/3 of tongue
Fungiform
68
What taste buds are on the posteiror margin of the tongue
Foliage
69
What taste buds are in the cleft
Circumvallate papillae
70
Where are taste receptor cells located
Taste buds
71
Where are taste buds most obvious
Tongue
72
How many cells does each taste bud contain
40-100
73
What are the 4 different functionally distinct cell types within the taste buds
- type I: mainly perform supportive functions
- type II: receptor cells posses G protein-coupled receptors for bitter, sweet, and umami compounds
- type III: secrete NT
- type IV: basal cells
74
Apical end of taste cells
Covered with microvilli of variable lengths that extend into taste pore
75
What does the taste pore allow
Contact between the microvilli of the taste cell and the external milieu
76
What mus the substances pass through to reach the taste cell microvilli
Protein rich substance of the taste pore
77
Taste tranduction
Just like all the others
| -chemicals react with receptors, increase intercellular Ca2+, results in a release of a chemical NT (serotonin)
78
The afferent fibers of first order taste neurons travel in the:
1. Facial nerve
2. Glossopharyngeal nerve
3. Vagus nerve
79
What nerve is responsible for taste on anterior 2/3 of tongue
Facial nerve (chorda tympani)
80
What innervates the soft palate
Greater superficial petrosal nerve
81
What innervates the posterior 1/3 of the tongue
Glossopharyngeal
82
What innervates the small area around the epiglottis
Vagus nerve
83
General sensation to the tongue
Trigeminal nerve
| -detecting temperature
84
The cell bodies of facial nerve fibers serving taste are located where
Geniculate nucleus
85
The primary afferent taste fibers enter the solitary tract and synapse on cells of the
Rostral solitary nucleus
86
Taste fibers in CN 9 and 10 have thei cell bodies of origin in the inferior ganglia of these CN
What is the primary taste nucleus
87
What is the principal visceral afferent nucleus of the brainstem
Solitary nucleus
88
How is the solitary nucleus divided
Rostral (gustatory) and caudal (visceral or cardiorespiratory) nucleus
89
Taste fibers traveling in CN7, 9, and 10 terminate primarily in the ____ portions of the solitary nucleus
Rostral
90
Axons arising from second order neurons in the gustatory nucleus (rostral solitary nucleus) ascend in the _____ central tegmental tract and terminate in the ________
Ipsilateral
| VPM
91
Axons from the neuron in the VPM travel where
Through the ipsilateral posterior limb of the internal capsule to terminate in the inner portion of the anterior insular cortex and on the lateral frontal operculum of the postcentral gyrus
92
This pathway (solitary nucleus--VPM00cortex) is responsible for what
The discriminatory aspects of taste and is exclusively ipsilateral
93
The sensation ear perceive when eating or drinking is the sensation of flavor, it is the result of the combination of three different kinds of input:
1. Direct chemical stimulation of taste buds
2. Stimulation of olfactory receptors by vapors from food
3. Stimulation of chemical sensitive and somatosensory free nerve endings of CNV (texture and temp)
94
Loss of taste sense, rare, would require injury to tongue or CN 7/9/10 afferent fibers
Ageusia
95
Decreased taste sensitivity
Hypogeusia
96
Distortions in taste perceptions
Parageusia/dysguesia
